Apple has won the right to keep its computers free of rival operating systems. Circuit Judge Mary Schroeder wrote in her opinion that Apple's Mac OS X licensing agreement was indeed enforceable against Psystar, which had sold non-Mac computers with Mac OS X installed.

Psystar claimed that the OS X licensing agreement was an "unlawful attempt to extend copyright protection to products that are not copyrightable."The Ninth Circuit chucked that idea out.

Pystar had been making hacktintoshes which ran OSx until Apple sued the outfit. In late 2009, US District Judge William Alsup ruled that Psystar violated Apple's copyrights when distributing Mac OS X with its machines.

The ruling is important for Apple because it means that it is legally justfied in keeping its oppressing control freak business model with its closed ecosystem. It means that the company can keep technological controls to ensure that only approved applications are used in connection with the operating systems.